Extractor spring retainer for a firearm



June 19, 1956 F. C. LA BORDE EXTRACTOR SPRING RETAINER FOR A FIREARM Filed March 24, 1953 IN V EN TOR.

Frunk ELLuEu-rda ATTORNEYS EXTRACTOR SPRING RETAINER FOR A FIREARM Frank C. La Borde, Springfield, Mass., assignor to the United States of America as represented by the Secretary of the Army Application March 24, 1953, Serial No. 344,483

Claims. (Cl. 89-1) (Granted under Title 35, U. S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to automatic firearms of the Browning Machine Gun type and relates more particularly to improvements in the cover member therefor.

Firearms of the Browning Machine Gun type are provided with a cover member which is hinged to the trunnion block and arranged to form a part of the top side of the receiver. The cover is provided with an integral flange which extends downwardly therefrom to form a housing for the components'of the cover group. One of these components is an extractor cam which is secured by rivets to the bottom side of the cover. Provided in the side of the extractor cam that abuts the cover, is an L- shaped recess which provides the means for releasably securing one end of an extractor spring.

conventionally, the cover and the extractor cam are fabricated separately from steel forgings. Production design has as its criteria ruggedness and simplicity of construction, economy of manufacture, and the utilization of noncritical material. Thus, it is desirable that the cover be fabricated from a casting of such material as pearlitic iron and for the extractor cam to be cast integral with the cover. The advantages of this means of fabrication are obvious. There are fewer undesirable structural stresses to contend with in castings than in forgings during manufacture and less material to be machined away. Further, it is economical in point of man hours saved, to fabricate the cover with an integral extractor cam than to manufacture the cover and the extractor cam separately and subsequently rivet them together. However, by fabricating the extractor cam integrally with the cover, it is diflicult to machine therein the aforementioned L-shaped recess for retaining the extractor spring. Therefore, in a cover having an integral extractor cam, new means must be provided for releasably securing the extractor spring to the extractor cam, or a new location for releasably securing the extractor spring established, which would require a modification of some of the components of the cover group.

It is the object of this invention to provide a means for securing a standard extractor spring to an extractor cam cast integrally in a cover member.

It is another object of this invention to provide a cover having an integral extractor cam with novel means for retaining existing, co-assembly parts without their being modified.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

Fig. l is a fragmentary bottom view of a cover showing the extractor spring and the extractor cam with a portion sectioned to show the extractor spring retainer of this invention arranged therein;

Fig. 2 is an end view of the extractor spring retainer;

nited States Patent ice Fig. 3 is a cross-sectional view taken along the line 3-3 of Fig. 1;

Fig. 4 is a fragmentary longitudinal sectional view showing the extractor spring retainer secured in the cover; and

Fig. 5 is a perspective view of the end of the extractor spring retained by the extractor spring retainer of this invention.

Shown in the figures is a substantially rectangular firearm cover 12 having an integral flange 13 which extends downwardly from an undersurface 14 to form therewith a housing 15. Provided in housing 15, integral with undersurface 14, is a cam portion 16 having an inclined surface which extends downwardly and rearwardly from undersurface 14, or from right to left in Fig. 1. Cam 16 is arranged in housing 15 spaced apart from the longitudinal portions of flange 13 and parallel thereto.

Provided laterally through a longitudinal side of cover 12 is a cylindrical bore 18 which traverses flange 13 and cam 16. A cylindrical hole 20 is provided vertically through cover 12, between flange 13 and cam 16, and is arranged to intersect the edge of bore 18. Snugly received by bore 18 is a cylindrical retainer member 21 which extends from the outer surface of flange 13 to the further side of cam 16. Retainer 21 is provided with a semi-cylindrical concavity 22, alignable with hole 20, and a rivet 23 is receivable by hole 20 and groove 22 to secure retainer 21 against movement in cover 12.

Provided through the lower portion of retainer 21, so as to be spaced apart from and parallel with the inner end thereof, is a segmental channel 24, chordal portion 25 of which is arranged substantially parallel to undersurface 14. The portion of retainer 21 between channel 24 and the inner end thereof, noted by 26, is provided with a substantially rectangular aperture 27 which provides communication between channel 24 and the interior of housing 15 and forms an undercut portion having a purpose to be explained hereafter.

Extending downwardly into the rear portion of housing 15 is a headed stud 29. Assembled in housing 15, between stud 29 and retainer 21, is an arched flat spring 30, the arched portion of which is arranged to press against undersurface 14. One end of spring 30 is bifurcated, as shown by 31, to provide slidable engagement with stud 29. The resilience of spring 30 normally biases bifurcated end 31 downwardly against the head of stud 29. The other end of spring 30 has a laterally projecting lug portion 32, slidably receivable through rectangular aperture 27 into channel 24. Provided in lug 32 is a longitudinal indentation 34, of substantially the same width as portion 26, which forms a downwardly depending lip 33 receivable by channel 24. The resilience of spring 30 biases lug 32 downwardly to engage portion 26 with indentation 34 and to maintain lip 31 in channel 24, thereby securing spring 30 in cover 12.

Thus, there can be seen that there is here provided a simple, rugged and economical means of retaining an arched flat spring in a firearm cover having an integrally formed cam without any modification of the co-assembly components.

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims are intended to include such variations.

I claim:

1. In a firearm having a receiver and a cover hingedly mounted thereto, an arched flat spring secured at one end to the cover, and a retainer transversely mounted in the cover, said retainer having an undercut portion for cooperation with the opposite end of said spring whereby said spring is resiliently retained in the cover.

2. In a firearm having a receiver and a cover hingedly' mounted thereto, a cam integral with the cover, an arched fiat spring secured at one end to the cover and provided at the opposite end with a protruding lug portion terminated by a lip portion arranged at right angles thereto, and a retainer transversely mounted in said cam, said retainer having an undercut portion arranged to receive said lip portion whereby said spring is resiliently retained in the cover.

3. A cover for a firearm, said cover being provided with an integral cam, a headed stud vertically mounted in said cover, an arched flat spring having a protruding lug at one end and an open elongated slot at the other to receive said stud, said lug being provided with a longitudinal indentation and a lip portion formed thereby, and a retainer transversely mounted in said cam, said retainer provided with a recess and a rectangular aperature arranged to receive said indentation and permit said lip to be received by said recess whereby said spring is resiliently retained in said cover by said stud and said retainer.

4. A housing member for a firearm having depending sides, a cam integral with said member, a spring provided at one end with a protruding lug portion terminated by a lip portion arranged at right angles thereto and at the other end by an open and elongated slot, a headed stud received by said slot, and a retainer transversely mounted through said cam and one side of said member,

t said retainer having an undercut portion arranged to receive said lip whereby said spring is resiliently retained in said member by said stud and said retainer.

5. A cover for a firearm, an extractor cam integral with said cover, said extractor cam being provided with a transverse cylindrical bore, a cylindrical retainer receivable by said bore and secured therein by a transverse rivet, a channel in said retainer separated from the end thereof by a segmental portion, a rectangular aperture arranged in said segmental portion to provide communication into said channel, a headed stud mounted vertically in said cover, and an extractor spring having a lug portion protruding from one end and an elongated slot arranged in the other end to receive said stud, said lug being provided with a longitudinal indentation receivable in said segmental portion and a downwardly depending lip portion engageable with said Channel whereby said extractor spring is releasably retained in, said cover by said stud and said retainer.

References Cited in the file of this patent UNITED STATES PATENTS 1,041,410 Benet et a1. Oct. 15, 1912 1,293,021 Browning Feb. 4, 1919 1,628,226 Browning May 10, 1927 1,803,349 Pfeiffer May 5, 1931 2,342,283 Hyde .s Feb. 22, 1944 2,365,087 Lanchester ..r Dec. 12, 1944 

